This study examined the speech behavior of well and depressed mothers during conversation with their 3-year-old children. The sample to date consists of 18 well and 10 depressed mothers. Given the general motor retardation, the reduced energy level and social withdrawal of depressed individuals, it was predicted that the speech patterns of depressed mothers would differ from the speech patterns of well mothers. It was found that depressed mothers vocalize less often than do healthy mothers. The children of the depressed mothers also show differences in their speech patterns when compared to the children of healthy women. They speak less to their mother while sitting and eating lunch with her. While waiting with their children for a doctor's visit the depresed women changed their speech pattern to one of increased production punctuated by many very brief pauses. Similarly, their children's speech increased in amount to more closely approximate that of normal children. This change does not occur in the speech of the children of healthy mothers. The overall pattern of behavior suggests that depressed mothers interact differently with their children than do healthy mothers. This may affect the quality of mother-child interaction. It is hypothesized that the reduced frequency of vocalizations by depressed mothers may reduce the reinforcing and socializing capacity of speech for her children. The differences in the behavior between the two groups of children indicate that these influences are already apparent and affecting the behavior of her three-year-old offspring.